1. FIELD OF THE INVENTION
The present invention relates to a tape cassette. More particularly, it relates to a tape cassette wherein an upper half casing and a lower half casing are assembled without any slip-out.
2. DESCRIPTION OF THE PRIOR ART
A tape cassette used for VTR etc. usually comprises an upper half casing (1) and a lower half casing (2) as shown in FIG. 1. In the assembly of the tape cassette, cylindrical projections (5'.sub.1), (5'.sub.2) mounted on the lower half casing (2) are respectively arranged on cylindrical projections (5".sub.1), (5".sub.2) mounted on the upper half casing (1) by superposing the upper half casing (1) to the lower half casing (2). The casings (1), (2) are fixed by screwing screw bolts (3.sub.3), (3.sub.5) after inserting the screw bolts from the cylindrical projections (5'.sub.1), (5'.sub.2) into the cylindrical projections (5".sub.1), (5".sub.2), respectively. Screw bolts (3.sub.1), (3.sub.2), (3.sub.4) are also inserted from the lower half casing (2) and screwed in the corresponding cylindrical projections mounted on the upper half casing (1). A lock plate (6) for a cover (not shown) and a spring (7) for the lock plate are fitted.
In prior art tape cassettes having the aforementioned structure, there is a possibility of disadvantageous failure for slipping off the uppper half casing (1) from the lower half casing (2) in the step transferring the superposed upper and lower half casings to the next screwing step in the assembly.